


Old Habits Die Hard

by Okaylittlebrother



Category: Supernatural
Genre: 10x3, Anal, Angst and Porn, Dark Sam Winchester, Demon Blood Addiction, Demon Dean, Knifeplay, Knight(s) of Hell, M/M, Porn With Plot, Rimming, Rough Sex, Sam Winchester's Demonic Powers, Sibling Incest, Smut, trigger warning
Language: English
Status: Completed
Published: 2014-07-30
Updated: 2014-07-30
Packaged: 2018-02-11 02:25:22
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,244
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2049819
Author URL: https://archiveofourown.org/users/Okaylittlebrother/pseuds/Okaylittlebrother
Summary: <blockquote class="userstuff">
              <p>Sam is iffy about where things are headed because of some things that happened with Demons in the past. He doesn't wanna go down that road again, Dean is pushing it and if Sam doesn't comply he's afraid Dean might kill him. So he gives in, because those eyes... man, those black eyes.</p>
            </blockquote>





	Old Habits Die Hard

**Author's Note:**

> I started writing this at 2:00 this morning. I am currently running on shit loads of coffee, a Five Hour Energy and zero hours of sleep. I wrote my sister a Destiel fic based on the 10x3 sneak peak on Tumblr so I decided to write one for my fellow Wincest shippers. Enjoy :]

"Do it." Dean encouraged in a low guttural growl. His eyes were pitch black. "It's all you."

Sam grabbed a fistful of Dean's hair and pulled his head back revealing the bare column of his brothers neck. He sucked harshly on his adams apple, enticing a moan from deep with in Dean.

The mission Dean had originally set out to do, mission being: kill his little brother with a Kobalt hammer; had been aborted minutes ago when Dean started taunting him with the "didn't you miss me's" and the "I know you want this, Sammy. So don't even try to deny it."

Sam sucked hard along Dean's neck, leaving a trail of dark hickey's in his wake. He sucked in a deep, much needed breath, taking in the glorious smell of his brother. "Dean.." He whined through clenched teeth, as he grazed his hardening denim clad cock against the older man's hip.

Dean sucked his bottom lip between his teeth, then cocked his head back a little to get a good look at his brother's face. Sammy was so gone on him. He shot him a devious smirk. "Go ahead, Sammy. You know you want this." Dean said matter of factly. He gyrated his hips into his tall little brother. "Look." Dean said cupping Sam's cock through the straining fabric of his jeans. When Sam let out a loud luscious moan, Dean chuckled. "You want me so bad, you're about to bust a nut in your jeans."

Sam sighed in frustration and dropped his Dean to Dean shoulder. "I can't, De. It's been so long. I don't want to mess up. Seven years.."

"Has it really been that long?"

Sam nodded on Dean's shoulder.

"You know what they say, 'once an addict, always an addict'." Dean huffed a laugh. C'mon baby brother," He said palming Sam's dick again, rubbing the flat of his palm against him. "And think about it, Sammy. It's not just _any_ blood. It's _my_ blood. Your big brothers." Dean continued.

Sam's cock twitched at the thought. Dean felt it against his hip and laughed. "Mm, see? You _do_ want it." Sam whined and pouted looking in Dean's eyes- which were green again-probably just for the moment. Dean grinned at his brother and slowly reached behind him, retrieving a small knife from his back pocket, "maybe-" he brought his hand back around and waved the knife at Sam, teasingly. "You need a little help.." He said slowly. He flicked the blade open and watched his brothers face. It made Sam jump a little.

Dean eyed his brother from underneath those long, blonde eyelashes. He gently slid the blade across Sam's cheek.

Sam's eyes widened as he felt the cold steel come in contact with is warm skin. "Dean.." He whimpered softly.

"Is that what you need, Sammy?" Dean purred as he leaned in close to his brother. Sam could feel Dean's breath hot on his face. "You need a little help?" He continued as he slowly ran the blade of the knife along the side of Sam's neck, the tip grazing against stubble on the way down. It sent a shiver down his spine. Dean heard him gulp. He blinked and his eyes were black. "Tell me what you need, baby boy." Dean demanded in a low, gravelly voice.

"I-I-" Sam let out a shaky breath, "I need a little help." He whimpered.

Dean looked at him and Sam held back a moan that threatened to slip. Those eyes. It felt like they were burning a hole through every layer of fabric he was wearing, through his skin, and right through his soul.

"Help with what?" Dean asked as he traced the outer edges of Sam's face with the blade. Dean loved that he was reducing his brother to a whiny moans because of a knife trailing across his delicate skin.

"De, please-" Sam asked in a choked whine.

That was consent enough for Dean. He stepped back, putting at least a foot between the two of them. He held the blade to his arm and firmly pressed down as he dragged the blade across his skin, crimson liquid trailing behind the shiny steel. He heard Sam moan.

Dean smiled and looked up at him, and pressed his thumb in the blood on his arm, bringing it up to Sam's mouth and smearing it on his bottom lip. "Is this what you wanted, baby boy?" Dean asked in a gruffly whisper.

Sam whined and closed his eyes as he sucked his lip into his mouth. He moaned as the metallic liquid came in contact with his tongue.

Dean teased him roughly with the palm of his hand, feeling Sam's member pulsate under his touch. He whined, that's when Dean gripped his brothers hips and guided him backward down the hallway- occasionally running into walls because he was too determined to get his younger brother out of his clothes to care- he'd slammed Sam's body against the doorframe, he let out a quiet groan.

"Give me...the knife." Sam panted as Dean was tearing him out of his shirt. With Sam's flannel and undershirt on the floor already, Dean willingly gave up the small pocket knife. He heard it as the blade swished open. He felt the steel against his collarbone, then a flash of pain following. He winced. Sam instantly ducked his head and and his tongue darted out from between those plump, pink, spit slicked lips to lap up the warm tangy liquid from his brothers damp skin.

Dean hand already work Sam's belt loose and was now fumbling with the button and the fly of his pants, once he was successful in getting them undone, he grabbed his brothers hips firmly to help guide him out of the denim, which were pushed off and kicked across the floor. He then hooked his thumbs under the waistband of his boxers and pulled them down and his dick bobbed free. Dean instantly took Sam's dick in his firm grip, tugging at it with long, slow strokes.

"Dean.." Sam moaned as he pushed his older brother from the doorway and further into the room. He was quick to help his overdressed brother out of his clothing as he kissed and moaned into his mouth feverishly.

Now undressed, Dean grabbed him by the arms and lead him to the bed, when he felt Sam's knees hit the edge, he pushed him back until his back came in contact with the mattress. He pumped his brother's cock with a quickness just to get him riled up a bit.

Dean watched as Sam's eyes squeezed shut and his head thrashed back on the mattress. He pumped his hand faster twisting on the up stroke, running hos thumb over them bead of pre-come on the tip. "Yeah, Sammy. You like that? You like when my fist is on your cock like that? Making it throb? Am I making you feel good, baby boy? Making you writhe and whine under me?"

"Y-yes, Dean!" Same said through a stained breath. So good. I wanna taste you again." He whined.

"Go for it, baby." Dean smirked as he braced himself with one arm, holding himself up over Sammy's head. The other hand still stroking Sam's dick. "I'm all yours." He said leaning down and kissing into the hot, wet, heat of his younger brother's mouth.

Sam slid the steel blade across Dean's chest and watched as blood dripped down onto his lips. He leaned up and swirled his tongue over and around the cut he made into his brother's skin. Dean groaned under his breath. "Damn, baby boy. That's so hot." He panted, feeling Sam's hot tongue on his skin. He winced as he swiped over it again. It stung a little bit, he didn't care.

Dean lifted Sam's head up to look at him. Dean smiled and brought his fingers to Sam's lips. "Get 'em nice and wet for me, sweetheart." Dean ordered almost in a growl. Sam had to squeeze the base of his cock to keep himself from coming right that second. Those black eyes turned him on so much. Dean slowly slid his index and middle fingers into Sam's mouth and began to feel his tongue twirling around them. He fucked Sam's mouth with his fingers as Sam watched him. "Gonna fill you up so good, baby brother. Get you nice and open so you take my cock real easy. Gonna pound that ass." He said as he pulled his fingers from Sam's mouth and brought them down to slick his puckered hole.

Dean pressed gently against his hole and watched him as he squirmed and writhed above him. Dean laughed as he slowly teased Sam's entrance. "Mm Sammy, I bet you're so fucking tight. I can't wait to slide my dick in you. Feel you clench around me. When's the last time you got laid, baby?" Dean laughed loudly and it dawned on him. _Everyone that sleeps with Sam Winchester ends up dead_. Dean slide the tip on his finger slowly passed the tight ring of muscle. "Good thing your big brother's a demon then, right?" He raised his eyebrow and slid his finger in further, pushing it in and pulling it out slowly. Sam moaned loudly. "God damn you're so tight, baby boy!- a Knight of Hell. That way I can fill you up when you ask for it, huh?" He started picking up the pace and it got to where he could add his second finger. Sam gasped loudly at the intrusion followed by a lustful moan, as he arched his back and began to fuck himself onto Dean's fingers. "Are you my little slut, Sammy?" Dean asked with a throaty growl as he began to push deeper into Sam, scissoring him open. "Are you a Knight of Hell slut?"

Sam moaned loudly and arched his back. "Yes- Yes, D-Dean!"

Dean pushed into him a few more times and pulled out, hearing him whine at the loss. Dean bit his lip and stretched out over Sam and reach for the nightstand drawer to grab out his bottle of lube. He felt a pinch in his thigh. "Ahh! Damn it, Sam!" He whipped his head around to look down at Sam with wide black eyes. He was smearing blood over his thigh and sam was seductively sliding his crimson color digit between his teeth and sucking on his obscenely, being sure not to miss any blood.

"God! Mmm I like green but black is so much hotter!" Sam explained still watching his brother and he came back his legs.

Dean laughed, "yeah?" Has he squeezed some lube on to his fingers and warming it up before smearing it over Sam's entrance. He lathered his cock with some lobe as well, stroking himself a few times for good measure.

"Yeah. They do things to me." He moaned with a smile.

"You ready,Sammy?" Dean asked lining himself up with his hands holding Sam's thighs.

"Yeah." Sam exhaled with a smile. "I'm ready."

Dean pressed the tip to Sam's slicked up hole and waited a second. He slowly pushed passed the tight ring of muscle. Dean groaned over Sam's moan. "God! You're so fucking tight, baby boy!" He pulled out again so just the head was in then he pushed back in slowly making Sam whimper.

It took a couple minutes before Sam was used to the thickness that breached his entrance, he relaxed and waited for Dean to set a comfortable pace. "Yeah, Sammy." Dean praised, gripping his hips so tightly that Sam was sure there'd be bruises in place of Dean's fingertips later on.

Sam threw his head back and moaned as Dean's hips started moving faster. Dean soon timed his thrusts with the pounding of the headboard hitting the wall. He lifted Sam's long legs over his shoulder so he could pound deeper into him.

Dean leaned down and peppered kisses across Sam's bare chest as he stroked his leaking cock. Sam thrust his hips into Dean's grip and moaned. His head lolling to the side before coming into contact with Dean's neck and biting kind of hard. Dean groaned, "damn Sammy, mark me up baby boy, let everyone know that i'm yours."

Dean sped up his pace trying to hit Sam's prostate with every thrust, making him cry out and grip the sheets tightly. Dean beamed down to take in the sight of wrecked, panting mess of a little brother. Dean's pocket knife held loosely in his hand. "C'mon, Sammy. I thought you wanted to taste your big brother?" He asked, the light above the bed reflected in his dark eyes. Sam propped himself up on his elbow and slowly made a few deep cuts on his brothers chiseled torso. "Mmm, yeah. I bet I taste way better than those other demon bitches you fucked back in the day, huh?"  Dean ask as he pounded relentlessly into his brother hitting his sweet spot once more.

"Yeah, so much better." Sam replied in a low fucked out voice. He felt Dean's tip hit his prostate that time. Sam groaned and as he threw his head back, "faster, Dean! Please?" He begged through moans. "I'm so close."

Dean complied with a sharp snap of his hips pounding into Sam over and over. The sound of his balls slapping against Sam's ass echoed throughout the room. Sam palmed his leaking cock and fucked his fist just as fast as Dean was driving into him.

Sam felt a heat pooling into his stomach. He undulated his body and he stroked his cock fiercely. "De! I'm gonna co- gonna!-"

Dean leaned down toward Sam and flashed his black eyes. His pink tongue ran along his swollen lips. "Come on, Sam! Come for your big brother." Dean cooed, keeping his dangerous black eyes on his brother and thrusting his hips into him.

Sam moaned and bit his lip as he started into his brothers eyes- as black as the deepest dark. His breathing hitched and he came with a shout, his release painting his hand and both- his and his brother's stomachs in thick white strands. Dean felt Sam clench around his cock, making Dean thrust hard and fast until he flooded Sam's channel.

Dean swatted Sam's hand away from his cock pumping up and down pushing him through his orgasm. He came twice more, his muscles contracting around Dean's cock. Dean moaned loudly coaxing himself through his own orgasm as well. Dean came a second time, in spurts that made his brother shudder underneath him. A salacious grin kept to the corners of his mouth as he listened to his brothers quavering fucked out moans.

Dean pulled out of him with a groan as he watched his release drip from his brother. He quickly folded his brother in half at the waist with dexterousness. His tongue lapped up his own seed, he pushed passed the ring of muscle as he tasted more of himself inside his brother. Dean looked up at his brother as he flicked and teased Sam's hole with his tongue. "You wanna taste me, Sammy? You wanna taste my come?"

 

"Please let me taste you.." Sam whimpered.

Dean hooked his thumbs in Sam's fucked out hole. He pushed his tongue in and out of Sam's ass lapping up more of his seed. He came up and mashed his lips with the younger man's. Sam parted his lips letting his brother in his mouth. Dean massaged his tongue with Sam's, kissing him deeply. "You taste that, baby boy?"

Sam nodded and moan as he grind into his Dean's leg. "Yeah. Taste so good, De."  Sam whimpered into his mouth.

Dean used his finger to wipe up the dripping blood on his chest and stomach, he brought the wet digit close to Sam's face for him to taste. A little of the blood that was on Dean's finger, dripped down to the side of Sam's mouth. He took ahold of Dean's hand and sucked on his finger, moaning around it, tasting his brothers salty, sweet, coppery blood.

Sam looked at Dean as he flopped down on the mattress beside him. "What does this mean, Dean?" He asked after a minute of complete silence, eye's still staring blankly at the white ceiling overhead. His voice quavering as he spoke.

"What does what mean?"

"Me- with the, uh..." He trailed off, gesturing to the blood on Dean's chest.

"With what?" His brow shot up in question. "The _demon_ blood?" He asked with a devious grin plastered on his face.

"Yeah." Sam replied in a whisper.

Dean pulled Sam close and some how in the process their legs got tangled together. "Hey," don't worry about that now. I just gave mind blowing sex- to the point where your limbs feel like Jell-O. And you're worried about a little demon blood? Relax, it was less that an ounce probably. Nothing will happen." He reassured proudly, holding the taller man closer to his body.

"It's just that...in the past..with Ruby....I don't know if I want that to happen again." Sam sighed and pressed his mouth against his brothers damp skin.

"Sammy, i'm a Knight of Hell." He said. "Soon-To-Be-King of Hell." He added matter of factly with a shit eating grin.

"So?"

" _So_?" Dean asked. He pulled back and looked at his brother in confusion. " _King. Of. Hel_ l, Sammy." He punctuated with his thumb and index finger pressed firmly together in the air.

"You're gonna be the new Crowley. Big deal."

"You're not excited to have: Dean Winchester- King of Hell, as your brother?"

Sam shrugged. You're totally making this about you." Sam sat up and supported his weight on his arm. "I have _demon blood_ surging through my veins. _Again_! Don't try to act like this is a subject I should take lightly."

"Hey, look on the brightside." Dean said, ghosting his fingertips up and down Sam's arm. "You could rule Hell with me." He said hopefully.

Sam looked at him and gave him a half smile. "Would you even like the thought of that?" He asked.

"Hell yeah I would, Sammy! You know damn well I would." He answered without hesitation.

Sam settled back into Dean's arms and kissed around his pectorals, "Okay." He answered contently.

"Good, i'd want nothing more than to have my baby brother by my side." Dean smiled.

Sam looked up at him and smiled at his words. "I love you, De."

Dean smiled and looked down at his brother. This was Sammy. Sam Winchester. It was familiar to him. He was family. He knew that since he was a demon now, emotion wasn't necessary anymore. This meat suit was his. Nobody elses. He knew how he felt toward his brother when he was human. He still thinks about it a lot. Even though he's probably going to be a demon for a very long time, he loved his brother and he wasn't going to change his fucking mind for anyone. He may be a demon; his worst nightmare. But nothing will ever change the love he has for Sammy. It's was there when he was human, it's gonna still be there when he's a demon. Nothing will ever change that.

 **  
**Dean pushed the long chestnut brown hair away from Sam's face, and gently pressed his lips against his forehead, planting a few kisses there. "I know." He mumbled.

**~FIN~**


End file.
